Summary of the invention
Technical problem to be solved by this invention provides the method and apparatus of a kind of Digital Down Convert, filtering extraction, and the prior art computational complexity is high to solve, poor stability, and operational precision is low, the problem of real-time difference.
In order to address the above problem, the invention provides the method and apparatus of a kind of Digital Down Convert, filtering extraction, concrete technical scheme is following:
A kind of method of Digital Down Convert comprises:
Receive digital intermediate frequency signal, said reception digital intermediate frequency signal is carried out the heterogeneous resolution process that heterogeneous factoring is n, obtain the signal and the output of the heterogeneous resolution process in n road;
Receive the signal of the heterogeneous resolution process in said n road, the signal of each heterogeneous resolution process in road is carried out Frequency mixing processing, obtain the signal and the output of n road Frequency mixing processing;
Receive the signal of said n road Frequency mixing processing, carry out the filtering extraction processing, obtain n/m way word down-conversion signal according to extracting the signal of factor m to said n road Frequency mixing processing;
Wherein, m, n, n/m are non-vanishing natural number, m≤n.
A kind of method of filtering extraction comprises:
Receive the signal X of n road Frequency mixing processing
N * 1, according to adding matrix A before the capable n row of j
J * nTo input signal X
N * 1Add matrix operation before carrying out, obtain capable 1 row of j before add the signal S of matrix operation
J * 1, the signal X of said n road Frequency mixing processing
N * 1Matrix form for capable 1 row of n;
To preceding adding the signal S of matrix operation
J * 1Carry out Filtering Processing, obtain the signal U of the Filtering Processing of capable 1 row of j
J * 1
According to adding matrix B behind the capable j row of n/m
(n/m) * jSignal U to Filtering Processing
J * 1Add matrix operation after carrying out, obtain capable 1 row of n/m after add the signal Y of matrix operation
(n/m) * 1, with after add the signal Y of matrix operation
(n/m) * 1As the Digital Down Convert signal;
Wherein, m, n, n/m are non-vanishing natural number, m≤n, j>=n.
A kind of digital down converter comprises:
Heterogeneous decomposition circuit is used to receive digital intermediate frequency signal, and said reception digital intermediate frequency signal is carried out the heterogeneous resolution process that heterogeneous factoring is n, obtains the signal and the output of the heterogeneous resolution process in n road;
Mixting circuit is used to receive the signal of the heterogeneous resolution process in said n road, and the signal of each heterogeneous resolution process in road is carried out Frequency mixing processing, obtains the signal and the output of n road Frequency mixing processing;
The filtering extraction circuit is used to receive the signal of said n road Frequency mixing processing, carries out filtering extraction and handles according to extracting the signal of factor m to said n road Frequency mixing processing, obtains n/m way word down-conversion signal;
Wherein, m, n, n/m are non-vanishing natural number, m≤n.
A kind of filter comprises:
Before add the matrix operation unit, be used to receive the signal X of n road Frequency mixing processing
N * 1, according to adding matrix A before the capable n row of j
J * nTo input signal X
N * 1Add matrix operation before carrying out, obtain capable 1 row of j before add the signal S of matrix operation
J * 1, the signal X of said n road Frequency mixing processing
N * 1Matrix form for capable 1 row of n;
Sub-filter unit is used for preceding adding the signal S of matrix operation
J * 1Carry out Filtering Processing, obtain the signal U of the Filtering Processing of capable 1 row of j
J * 1
After add the matrix operation unit, be used for according to adding matrix B behind the capable j of the n/m row
(n/m) * jSignal U to Filtering Processing
J * 1Add matrix operation after carrying out, obtain capable 1 row of n/m after add the signal Y of matrix operation
(n/m) * 1, with after add the signal Y of matrix operation
(n/m) * 1As the Digital Down Convert signal;
Wherein, m, n, n/m are non-vanishing natural number, m≤n, j>=n.
Technical scheme provided by the invention has reduced hardware processor performance demands and power consumption through signal is carried out heterogeneous resolution process; Utilize output tributary signal to be kept in the signal of filtering extraction circuit with Frequency mixing processing to carry out computing; The output tributary signal of treating extraction abandons, and obtains the Digital Down Convert signal, thereby has reduced the streamline grade; Reduced computational complexity; Improve processor stability, simultaneously, effectively improved operational precision and computing real-time.
Embodiment
Core concept of the present invention is: through signal is carried out heterogeneous resolution process, reduced hardware processor performance demands and power consumption; Utilize output tributary signal to be kept in the signal of filtering extraction circuit with Frequency mixing processing to carry out computing; The output tributary signal of treating extraction abandons, thereby obtains the Digital Down Convert signal, has reduced the streamline grade; Reduced computational complexity; Improve processor stability, simultaneously, effectively improved operational precision and computing real-time.
Below in conjunction with accompanying drawing and preferred implementation technical scheme of the present invention is elaborated.
In order to realize goal of the invention of the present invention, the present invention has designed a kind of filtering extraction circuit, and the input and output equation of this filtering extraction circuit can be write as Y
(n/m) * 1=B
(n/m) * jH
J * jA
J * nX
N * 1Form, wherein Y
(n/m) * 1Expression filtering extraction circuit output signal is the matrix form that the n/m capable 1 that the signal that obtains behind the filtering extraction is write as is listed as; X
N * 1Be the input signal of filtering extraction circuit, can be write as the matrix form of capable 1 row of n; A
J * nFor adding matrix before the capable n row of j, to input signal X
N * 1Add matrix operation A before carrying out
J * nX
N * 1, just with A
J * nEach the row and X
N * 1Carry out dot-product operation, obtain the sub-filter unit input signal of capable 1 row of j, be designated as S
J * 1H
J * jRepresenting sub-filter unit, is to preceding adding the output signal S of matrix operation
J * 1Carry out Filtering Processing, just each row is input to the sub-filtering system Filtering Processing of corresponding row, obtain the signal of the Filtering Processing of capable 1 row of j, be designated as U
J * 1B
(n/m) * jFor adding matrix behind the capable j of the n/m row, according to after add the signal U of matrix to Filtering Processing
J * 1Add matrix operation after carrying out, just with B
(n/m) * jEach the row and U
J * 1Carry out dot-product operation, obtain the output signal Y of the filtering extraction circuit of capable 1 row of n/m
(n/m) * 1Here, n, m and n/m are non-vanishing natural number, preferably, and m≤n, j>=n.
Carry out detailed description by way of example in the face of the method for designing of filtering extraction circuit down, but this instance does not constitute the restriction to protection range of the present invention.
If a certain filter system unit impact response h is 2 to be decomposed into h according to factoring
0(n) and h
1And satisfy (n),
0≤k≤(N-1)/2, N is non-vanishing natural number (1)
Pending signal x (n) used the same method be decomposed into
0≤k≤(N-1)/2, N is non-vanishing natural number (2)
Result y (n) used the same method be decomposed into
0≤k≤(N-1)/2, N is non-vanishing natural number (3)
If h
0(n) and h
1(n) Z-transformation is remembered into H respectively
0And H
1, x
0(n) and x
1(n) Z-transformation is remembered into X respectively
0And X
1, y
0(n) and y
1(n) Z-transformation is remembered into Y respectively
0And Y
1, then filter input and output equation can be written as
Write formula (4) as matrix form, can be obtained the input and output equation of filter
According to formula (5), if the filtering extraction circuit has only kept Y
0Branch road, then corresponding input and output equation does
Adding matrix before in the formula (6) does
Sub-filter unit is diag
After to add matrix be [1 z
-2], according to formula (6), can obtain degree of parallelism and be 2 filtering extraction circuit structure, as shown in Figure 1.
According to formula (5), if the filtering extraction circuit has only kept Y
1Branch road, then corresponding input and output equation does
Formula (7) in front of the matrix?
Sub-filtering unit for the diag?
added matrix [-1? 1? -1].According to formula (7), can obtain degree of parallelism and be 2 filtering extraction circuit structure, as shown in Figure 2.
It should be noted that factoring all is 2 with extracting the factor for better explanation filtering extraction circuit structure here, so formula (6) and formula (7) they possibly not be simplest formulas, under the simplest formula situation, preceding add matrix and after add matrix and possibly be unit matrix.
Use same quadrat method, can obtain the filtering extraction circuit structure of any degree of parallelism.For example, if be heterogeneous input form { x (4k), x (4k+1) with the pending signal decomposition of filtering extraction circuit; X (4k+2), x (4k+3) }, simultaneously; The system unit impulse response coefficient h of filter is carried out heterogeneous decomposition { h (4k), h (4k+1), h (4k+2); H (4k+3) }, y (4k) and two branch roads of y (4k+2) are abandoned, it is as shown in Figure 3 then to obtain degree of parallelism and be 4 filtering extraction circuit structure.
One embodiment of the present of invention provide a kind of method of Digital Down Convert, and are as shown in Figure 4, comprising:
401, receive digital intermediate frequency signal, carry out the heterogeneous resolution process that heterogeneous factoring is n to receiving digital intermediate frequency signal, obtain the signal and the output of the heterogeneous resolution process in n road;
402, receive the signal of the heterogeneous resolution process in n road, the signal of each heterogeneous resolution process in road is carried out Frequency mixing processing, obtain the signal and the output of n road Frequency mixing processing;
403, the signal of reception n road Frequency mixing processing carries out the filtering extraction processing according to extracting the signal of factor m to said n road Frequency mixing processing, obtains n/m way word down-conversion signal; Wherein, m, n, n/m are non-vanishing natural number, m≤n.
Further, carry out filtering extraction and handle the step that obtains n/m way word down-conversion signal and comprise according to extracting the signal of factor m said n road Frequency mixing processing:
According to adding matrix A before the capable n row of j
J * nSignal X to n road Frequency mixing processing
N * 1Add matrix operation before carrying out, obtain capable 1 row of j before add the signal S of matrix operation
J * 1, the signal X of this n road Frequency mixing processing
N * 1Be the matrix form of capable 1 row of n, j>=n, j are non-vanishing natural number;
To preceding adding the signal S of matrix operation
J * 1Carry out Filtering Processing, obtain the signal U of the Filtering Processing of capable 1 row of j
J * 1
According to adding matrix B behind the capable j row of n/m
(n/m) * jSignal U to Filtering Processing
J * 1Add matrix operation after carrying out, obtain capable 1 row of n/m after add the signal Y of matrix operation
(n/m) * 1, with after add the signal Y of matrix operation
(n/m) * 1As the Digital Down Convert signal.
Digital down converter structure chart below in conjunction with shown in Figure 5 carries out detailed description to first embodiment, but this example does not constitute the restriction to protection range of the present invention.In Fig. 5, this low-converter comprises: heterogeneous decomposition circuit, mixting circuit and filtering extraction circuit.Particularly,
The digital intermediate frequency signal of supposing input is x (n), and heterogeneous factoring is n=2.Confirm to extract factor m=2 according to the signal to noise ratio requirement of system and the disposal ability of field programmable gate array (FPGA, Field-Programmable Gate Array) chip, need guarantee to satisfy is that Qwest's sampling thheorem gets final product.
Heterogeneous decomposition circuit obtains the signal after the 2 tunnel heterogeneous resolution process after the signal x (n) of input is carried out heterogeneous resolution process:
In this example, heterogeneous factoring is 2 just in order to describe simple usefulness, in the practical application, can utilize heterogeneous decomposition circuit to carry out factoring and be any non-vanishing natural heterogeneous resolution process.
Mixting circuit is to realize Frequency mixing processing through the signal multiplication of local oscillation signal and the output of heterogeneous decomposition circuit.If it is the heterogeneous decomposition of n that heterogeneous decomposition circuit has carried out factoring, then the local oscillation signal of each branch road of mixting circuit also will carry out the heterogeneous decomposition that factoring is n.Because the heterogeneous factoring n=2 of heterogeneous decomposition circuit, correspondingly, mixting circuit comprises 2 mixing branch circuits, and wherein, first branch circuit of mixting circuit receives first via signal f
X0(n)=and x (2n), second branch circuit of mixting circuit receives the second road signal f
X1(n)=x (2n+1).The centre frequency of supposing pending digital intermediate frequency signal is f
c, sample frequency is f
s, then 2 road local oscillation signals on I road are:
2 road local oscillation signals on Q road do
Then the mixing results of each branch road of I road does
The mixing results of each branch road of Q road does
The filtering extraction circuit carries out the filtering extraction processing to the I road signal of mixing and the Q road signal of mixing.
Particularly, the Q road signal of the I road signal of mixing and mixing being input to two same filtering extraction circuit respectively handles.Below in conjunction with formula (7) corresponding hardware structure, the application process of filtering extraction circuit is described.
Add matrix operation, the preceding matrix that adds before the I road signal of formula (11) Frequency mixing processing has carried out earlier
First line display carry out computing 1s
I0(n)+0s
I1(n)=s
I0(n), the second line display computing 1s
I0(n)+1s
I1(n)=s
I0(n)+s
I1(n), the third line is represented computing 0s
I0(n)+1s
I1(n)=s
I1(n); Before add the matrix operation result and get into sub-filter unit diag again
Add 3 road signals that matrix operation obtains before being about to and pass through H respectively
0, H
0+ H
1And H
1Subfilter is carried out Filtering Processing, obtains H respectively
0s
I0(n), (H
0+ H
1) (s
I0(n)+s
I1And H (n))
1s
I1(n) three tunnel filtered signals; Sub-filter unit is exported and is added matrix [1 1-1] after signal gets into again, has just obtained the output signal after the Digital Down Convert and has been:
-H
0s
I0(n)+(H
0+H
1)(s
I0(n)+s
I1(n))-H
1s
I1(n)=H
0s
I1(n)+H
1s
I0(n) (13)
If with this filtering extraction circuit of the input of the signal after the Q road mixing of formula (12), this filtering extraction circuit is output as the Digital Down Convert signal, the result is following:
-H
0s
q0(n)+(H
0+H
1)(s
q0(n)+s
q1(n))-H
1s
q1(n)=H
0s
q1(n)+H
1s
q0(n) (14)
Wherein, the structure of a complete digital down converter is as shown in Figure 6, and wherein, the heterogeneous factoring of heterogeneous decomposition circuit is 4, and the degree of parallelism of filtering extraction circuit is 2, and extracting the factor is 2, and input signal is x (4k), and down-conversion signal is y
Q0, y
Q1, y
I0And y
I1The structure of the digital down converter that another is complete is as shown in Figure 7, and wherein, the heterogeneous factoring of heterogeneous decomposition circuit is 8, and the degree of parallelism of filtering extraction circuit is 4, and extracting the factor is 2, and input signal is x (4k), and down-conversion signal is y
Q0, y
Q1, y
Q2, y
Q3And y
I0, y
I1, y
I2, y
I3
Based on the inventive concept identical with method, the embodiment of the invention provides a kind of digital down converter, and is as shown in Figure 5, comprising:
Heterogeneous decomposition circuit is used to receive digital intermediate frequency signal, carries out the heterogeneous resolution process that heterogeneous factoring is n to receiving digital intermediate frequency signal, obtains the signal and the output of the heterogeneous resolution process in n road;
Mixting circuit is used to receive the signal of the heterogeneous resolution process in said n road, and the signal of each heterogeneous resolution process in road is carried out Frequency mixing processing, obtains the signal and the output of n road Frequency mixing processing;
The filtering extraction circuit is used to receive the signal of said n road Frequency mixing processing, obtains n/m way word down-conversion signal according to extracting the signal of factor m to said n road Frequency mixing processing;
Wherein, m, n, n/m are non-vanishing natural number, m≤n.
Further, this filtering extraction circuit comprises:
Before add the matrix operation unit, be used for according to adding matrix A before the capable n of the j row
J * nSignal X to n road Frequency mixing processing
N * 1Add matrix operation before carrying out, obtain capable 1 row of j before add the signal S of matrix operation
J * 1, the signal X of this n road Frequency mixing processing
N * 1Be the matrix form j>=n of capable 1 row of n, j is non-vanishing natural number;
Sub-filter unit is used for preceding adding the signal S of matrix operation
J * 1Carry out Filtering Processing, obtain the signal U of the Filtering Processing of capable 1 row of j
J * 1
After add the matrix operation unit, be used for according to adding matrix B behind the capable j of the n/m row
(n/m) * jSignal U to Filtering Processing
J * 1Add matrix operation after carrying out, obtain capable 1 row of n/m after add the signal Y of matrix operation
(n/m) * 1, with after add the signal Y of matrix operation
(n/m) * 1As the Digital Down Convert signal.
Based on the inventive concept identical with method, the embodiment of the invention provides a kind of filter, and is as shown in Figure 8, comprising:
Before add the matrix operation unit, be used to receive the signal X of n road Frequency mixing processing
N * 1, according to adding matrix A before the capable n row of j
J * nTo input signal X
N * 1Add matrix operation before carrying out, obtain capable 1 row of j before add the signal S of matrix operation
J * 1, the signal X of this n road Frequency mixing processing
N * 1Matrix form for capable 1 row of n;
Sub-filter unit is used for preceding adding the signal S of matrix operation
J * 1Carry out Filtering Processing, obtain the signal U of the Filtering Processing of capable 1 row of j
J * 1
After add the matrix operation unit, be used for according to adding matrix B behind the capable j of the n/m row
(n/m) * jSignal U to Filtering Processing
J * 1Add matrix operation after carrying out, obtain capable 1 row of n/m after add the signal Y of matrix operation
(n/m) * 1, with after add the signal Y of matrix operation
(n/m) * 1As the Digital Down Convert signal;
Wherein, m, n, n/m are non-vanishing natural number, m≤n, j>=n.
In the technical scheme provided by the invention,, reduced hardware processor performance demands and power consumption through signal is carried out heterogeneous resolution process; Utilize output tributary signal to be kept in the signal of filtering extraction circuit with Frequency mixing processing to carry out computing; The output tributary signal of treating extraction abandons, and obtains the Digital Down Convert signal, thereby has reduced the streamline grade; Reduced computational complexity; Improve processor stability, simultaneously, effectively improved operational precision and computing real-time.
Scheme according to the invention is not restricted to listed utilization in specification and the execution mode.Under technology of the present invention, the those of ordinary skill in field, can make various corresponding changes and distortion, and all these corresponding changes and distortion all belong to the protection range of claim of the present invention according to the present invention.